Pliers



Dec. 8, 1970 F. PATRICK 3,545,315

i PLIERS v Filed May 9, 1968 i242 Sheets-Sheet 1 ATTRNIEY Dec. 8, 1970 lF. PATRICK 3,545,315

` PLIERs v Filed May `9, 196e Y 2' sheets-sheet z INVENTOR ATTORNEYUnited States Patent 3,545,315 PLIERS Frank Patrick, Meadville, Pa.,assigner to Channellock, Inc., Meadville, Pa., a corporation ofPennsylvania Filed May 9, 1968, Ser. No. 727,815 Int. Cl. BZSb 7/12 U.S.Cl. 81-368 8 Claims ABSTRACT OF THE DISCLOSURE The shock of releasingtoggle pliers is reduced by cushion bumpers on the release lever whichtake effect rwhen the toggle links reach the opening side of deadcenter. The effect is a two stage release where the heavy pressure isdissipated before the parts are allowed to move to the full openposition. In a preferred form, the bumper of the release lever issqueezed against the actuating lever which comprises one of the togglelinks.

This invention is intended to improve the operation of toggle or visegrip pliers by the use of appropriately arranged cushion bumpers toreduce the shocks which accompany release of the gripping pressure. In apreferred form where the release is effected by a release lever which issqueezed against the actuating lever, the cushion bumper is arrangedbetween the release and actuating levers and in effect results in a twostage opening of the pliers. During the first stage the toggle linksmove from dead center to the opening side of dead center and the heavyclosing pressure of the jaws of the work is released. Since the movementof the jaws at this stage is slight, the momentum of the parts is smalleven through the pressures which are released are huge. During thesecond stage, the jaw opening spring moves the actuating lever to itsfull open position in readiness to receive another work piece.

In the drawing, FIG. 1 is a side elevation of a toggle pliers in thefull open position, FIG. 2 is a section on line 2-2 of FIG. 1, IFIG. 3is a side elevation of the pliers in the closed position, FIG. 4 is aview similar to FIG. 2 of a modification, FIG. 5 is a side elevation ofanother form of toggle pliers in the closed position, and FIG. 6 is aside elevation showing the FIG. 5 pliers with the actuating lever movedto the opening side of dead center.

In the pliers shown in FIGS. 1-4 inclusive, a handle 1 carries a xed jaw2 at its front end and has its backk end 3 internally threaded toreceive an adjusting screw 4 which may be turned by a knob 5. Theadjusting screw may be locked in adjusted position by a lock nut 6 whichmay be tightened against a shoulder 7 on the end 3 of the handle toprevent turning of the adjusting screw. Associated with the stationaryjaw is a movable jaw 8 pivoted at 9 on the handle and urged toward theopen position by a coil spring 10l stretched between an ear 11 on thehandle and an eye 12 on the movable jaw. The handle 1 is convenientlymade of channel cross section except at the end 3 where the handle isformed to a curved section so that it may be internally threaded tocooperate with the adjusting screw 4. The channel section permits themajor portion of the spring 10 to be housed between the sides of thechannel.

Pivoted to the movable jaw 48 in an actuating lever 14 of channelsection with its sides straddling the end 15 of a toggle lever 16extending between a pivot abutment 17 on the inner end of the adjustingscrew 4 and a common pivot 18 between the levers 14 and 16. The pivots13, 17 and 18 together with the intermediate portions of the actuatinglever 14 and the lever 16 form a toggle joint which in FIG. 1 is shownin the re- Patented Dec. 8, 1970 laxed or open position. In order todevelop gripping pressure between the jaws 2, 8 and an interposed workpiece 19, the hand grip portion 20 of the actuating lever 14 is squeezedtoward the handle 1, bringing the pivots 13, 17 and 18 to the deadcenter or pressure position shown in FIG. 3. Because of the toggleaction, huge forces can be developed between the jaws 2 and 8. The dead4center position of the toggle is determined by the position of theabutment 17 on the end of the adjusting screw 4. For thick work pieces,the abutment 17 is moved to the right as viewed in FIG. 3, while forwork pieces thinner than the work piece 19, the abutment is moved to theleft. IFor repetitive work, it is desirable that once the abutment 17has been adjusted to the desired position for the particular thicknessof work piece, the adjusting screw 4 be locked in place as isconventiently done by the lock nut 6.

In the pressure or gripping position shown in FIG. 3, a projection 21aon the leve-r 16 bottoms on the bottom wall 22 of the channel section ofthe actuating lever and a projection 21 on the lever 16 projects througha slot 23 in the bottom wall 22 so that the end 24 of the projectionbears against the bottom wall 25 of a channel shaped release lever 26pivoted at 27 on the actuating lever 14. The release lever 26 straddlesthe actuating lever 14 and the bottom wall 25 preferably conformsgenerally to the shape of the bottom `wall of the actuating lever. Torelease the grip of the jaws 2, 8 on the intervening work piece, thehand grip section 28 of the release lever is squeezed toward the outersurface of the actuating lever. This causes the actuating lever 14 to bepivoted in a clockwise direction about the pivot 13. When the actuatinglever reaches the position indicated roughly by dotted lines 29, thecommon pivot or knee 18 of the toggle is moved to the jaw opening sideof dead center. At this stage, the clamping pressure between the jaws issubstantially released although the jaws have not opened appreciably.When the actuating lever reaches the dotted line position 29, it strikesan elastomeric coating 30` on the hand grip section 28 of the releaselever. This cushions the shock. Because of the relatively slight motion,the momentum of the actuating lever and the connected parts has notbuilt up to a high level and only a thin coating 30 of elastomer isneeded to reduce the shock to a comfortable level. The coating 30 notonly makes the pliers more comfortable to the user but it also preventsdamage to the pivot pins. When the pressure is released in a singlestage, the full jaw pressure is available to accelerate the parts andwhen these parts are stopped in the full open position, the shock on thepivot pins has been sufi'icient to bend or break the pins.

In the second stage of opening', the operator merely releases his gripon the release lever 26 and the spring 10 moves the pliers to the fullopen position. While the motion in the second stage of opening is large,the forces are not great because this motion is effected by the tensionspring 10.

Since only the portion of the elastomeric coating 30 adjacent therelease lever 14 is effective in absorbing shock, it is possible to useelastomeric bumpers 31 on the under side of the hand grap section 28 ofthe release lever as shown in FIG. 4. The bumpers 31 is positioned so asto make contact with the release lever 14 when it reaches the lfirststage of opening indicated by the dotted line 29.

In FIGS. 5 and 6 the two stage opening is shown in connection with thepliers of the type shown in Pat. 2,997,903. As there shown, the handle31 has a fixed jaw 32 at one end and at the other end has a generallyrectangular section 33 on which is mounted a tiltable locking slide 34which is biased to the left as viewed in FIG. by a tension spring 35connected between point 36 on the slide and point 37 on a movable jaw 38pivoted at 39 on the handle 31. The effect of the spring 35 is to closethe jaw 38 on the stationary jaw 32 with an initial pressure which isdetermined by the tension of the spring 35. The jaw can be opened bygrasping the slide 34 in the region indicated by the numeral 40 andsliding it backward or to the right as viewed in FIG. 5. Upon release ofthe slide, the spring 35 will automatically close the jaws of the workunder light pressure. The full gripping pressure is developed by anactuating lever 41 of channel section pivoted at 42 on the movable jaw38 and pivoted at 43 on a link 44 pivoted at 45 to the lower end of theslide 34. The pivot 45 is offset far enough from the center of the slide34 so that a force to the right as viewed in FIG. 5 tilts the slidethrough an angle suflicient to case it to lock upon the handle section33. As the actuating lever 41 is moved toward the closed position shownin FIG. 5, the pivot pin 43 which constitutes the knee of the toggle ismoved to the dead center or full pressure position. In this position, astop or projection 46 on the link 44 engages the bottom Wall of theactuating lever 41.

The gripping pressure between the jaws is released by a release lever 47of channel section pivoted on the pivot 43 and having an ear 48 whichengages a shoulder 49 on the handle 31. To release the pressure, thehand grip section 50 of the release lever is squeezed, causing the ear48 to cam the actuating lever to the release side of dead center. Inthis position shown in FIG. 6, the release lever 47 telescopes over andis in conforming engagement with the actuating lever 41 and the shock orimpact of the initial or rst stage opening is absorbed by an elastomericcoating 51 corresponding to the coating 30. This releases the pressurebetween the jaws but does not cause substantial opening. The momentum tobe absorbed is accordingly small. The second stage of opening iseffected by release of the hand grip portion 51 of the release lever 47,permitting the spring 35 to move the actuating lever 41 to the full openposition indicated by dotted lines 52. Since the opening motion of thesecond stage takes place under the action of spring 35, the forces arerelatively small compared to those developed during the initial stage ofopening.

What is claimed is:

1. In a plier type toggle wrench having a handle with a stationary jawat its front end, a movable jaw pivoted to said front end of the handle,toggle means for forcing the movable jaw toward the stationary jawincluding an actuating lever having one end pivoted to the movable jawand the other end with a hand grip section spaced from and opposite theback end of the handle, an adjustable abutment on the handle, a togglelever having one end pivoted to the abutment and the other end 4 pivotedto the actuating lever between its ends, the movable jaw being forcedtoward the stationary jaw by squeezing the hand grip section of theactuating lever toward the handle to bring the common pivot between theactuating lever and the toggle lever into dead center relation with theother pivots, a release lever pivoted on the actuating lever for pryingthe hand grip section of the actuating lever away from the handle tobring the common pivot between the actuating and toggle levers to therelease side of dead center remote from the handle, said release leverhaving a resilient bumper engaged by the actuating lever as the commonpivot moves to said rev lease side offdead center to absorb the momentumof the actuating and toggle levers.

2. The structure of claim 1 in which the release lever is squeezedtoward the handle to pry the actuating lever to said release side ofdead center.

3. The structure of claim 1 in which the bumper is positioned to engageactuating lever at a stage when the pressure between the jaws issubstantially released but prior to substantial opening of the jaws.

4. The structure of claim 1 in which the pliers includes spring meansurging the actuating lever away from the handle a further distance afterengagement of the bumper whereby upon release of squeezing pressureapplied to the release lever the actuating and toggle levers effect afurther release of pressure between the jaws.

5. The structure of claim 4 in which the spring means causes movement ofthe jaws to the full open position.

6. The structure of claim 1 in which the release lever is of channelsection adapted to telescope over the actuating lever, the forward endof the release lever being pivoted on the actuating lever and the backend of the release lever normally outstanding from the actuating leverin position to lbe squeezed against the release lever to pry theactuating lever to the release side of dead center.

7. The structure of claim '6 in which the bumper is a coating ofresilient material on the back end of the release lever.

8. The structure of claim 1 in which the back end of the handle isthreaded to receive an adjusting screw for positioning the adjustableabutment and a lock nut on the adjusting screw may be tightened againstthe back end of the handle to lock the adjustable abutment to thehandle.

References Cited UNITED STATES PATENTS 2,576,286 11/ 1951 Eisenberg81-371 2,997,903 8/1961 Rommel et al 8l-372X ROBERT C. RIORDON, PrimaryExaminer ROSCOE V. lPARKER, JR., Assistant Examiner

